Past methods for operating computer-controlled engines having fuel injection and dual-ignition systems has resulted in inflexible computerized controlled systems. These systems typically depend on programmed algorithms that control the engine parameters which provide improved operation under conditions anticipated by the computer program. To add, delete or change any of the engine parameters requires an external computer to input any user-desired customized changes. These engine control systems may be designed as original equipment or designed to replace conventional carburetor input engines. In either case, the system must be able to adjust the engine to various throttle demands, fuel-air mixtures, altitude, rpm, etc. To control these engine parameters, the system must receive and process various inputs from the engine. In addition to the dynamic requirements, there also remains the physical compatibility of the retrofit-design system to convert carburation based engines to electronic fuel injection system.
Presently there are two types of electronic fuel injection systems. These are throttle body injection and port injection.
Throttle body injection implies that the fuel injectors themselves are mounted in a throttle body, where the system functions much as a computer-controlled carburetor. This implementation has the drawback of not being able to meter fuel separately for each engine cylinder.
Port injection mounts the injectors near the intake valve of each cylinder, at the cylinder's intake port. Early systems fired the injectors in banks to simplify the controlling electronics however, this resulted in fuel puddling at the intake valve. Recently, the port style systems have been improved such that they time the injection pulse for each injector and eliminate the fuel puddling and provides better fuel atomization and throttle response. This type of port injection is also referred to as sequential port injection.
The engine control system of the instant invention has the injectors mounted in a throttle body therefore, it can be considered a throttle body injection system. However, since it injects fuel metered to the individual needs of each cylinder, it also has the advantages of a sequential port injection system. Therefore, it is referred to as sequential throttle body injection which can be used on multiple cylinder engines and allow a throttle body injection system to provide most of the performance benefits of a sequential port injection system, at a much lower installed cost.
Additionally, the present invention includes a user-friendly firmware program and an external input/output port. The program is accessed by a control display unit that is operated by only three push-button switches and the port allows an external input unit, such as a computer or modem, to be connected to further expand the selection and control of system parameters.
Because of the considerable increase in power and fuel efficiency provided by a user-programed, fuel injection engine, it is desirable to produce an engine control system that will overcome the problems and limitations of the prior-art systems. Therefore, it is important to anyone making such an investment and conversion that the system be designed to minimize mechanical problems and be both user friendly while maximizing user performance.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention, however the following U.S. patents were considered related:
______________________________________ U.S. PAT. NO. INVENTOR ISSUED ______________________________________ 5,174,263 Meaney 29 December 1992 5,091,858 Paielli 25 February 1992 5,088,464 Meaney 18 February 1992 4,955,348 Budde et al 11 September 1990 ______________________________________
The Meaney U.S. Pat. Nos. 5,174,263 and 5,088,464 disclose an engine management system specifically designed to manage the operation of a V-twin motorcycle engine. The system includes a throttle body and a throttle. The throttle body has an air intake manifold that mounts over the cylinder intake ports and the throttle which is operated by an operator, admits combustion air into the manifold. A pair of fuel injectors are mounted on the throttle body and respond to electronic injector control signals for injecting fuel into the air intake manifold. Fuel is delivered by a fuel pump which is regulated by a pressure regulator. An engine speed sensor supplies a signal that represents engine speed and a pressure sensor supplies a signal that represents the combustion air available in the manifold. The two signals are processed by an electronic controller in a look-up table that is addressed as a function of the speed and pressure signals. The injector control signals are then generated from data obtained in the look-up table.
The 5,091,858 Paielli patent discloses an electronically controlled engine fuel delivery system. The system includes a fuel injector and a plurality of sensors. The fuel injector is responsive to electronic control signals for delivering fuel to the engine cylinders and the sensors provide signals corresponding to engine operating conditions to a microprocessor based electronic control unit. The unit includes a memory that stores engine control parameters in several look-up tables. The tables are periodically addressed and thereafter supply control signals to operate the fuel injectors. The control unit includes circuitry for up-loading selected tables for the memory, monitoring engine operation as reflected by addressing of the parameters tables in real time and selectively initiating a programming mode of operation that continues uninterrupted.
The 4,955,348 Budde et al patent discloses a fuel injection conversion system fop V-twin motorcycles. The system includes an intake manifold having separate ducts that deliver a fuel and air mixture separately to each cylinder. A pair of fuel injectors mix the fuel from the injector with air drawn into the engine cylinders through the intake manifold. The individual pressurized fuel flow delivered to each injector is provided by a fuel distributor that is applied the pressurized fuel from the fuel source by a fuel pump.
The system also includes a fuel flow pressure regulator disposed in the fuel delivery system for controlling the pressure of the fuel flow delivered by the distributor to the injectors. To determine when the ignition system of the engine delivers an electronic pulse to fire the spark plugs, an electronic sensing means is included. The system also includes a status sensing means for measuring a combination of air and engine temperatures and the vacuum in the intake manifold. The combination of the electronic and status sensing means produce an electronic signal which operates the fuel injectors at the proper time and duration to deliver the proper amount of fuel to the cylinders of the engine by timed injection.
The Budde system as differs from the applicant's engine control system in that the Budde system:
1. is designed for motorcycle engines having two cylinders, an ignition system and a fuel source, The applicant's system is adaptable to any engine and includes its own ignition system.
2. requires and is secured to an intake manifold having separate ducts. The applicant's system does not require a special manifold it simply bolts to any manifold of directly to a cylinder head.
3. requires the use of a fuel distributor. The applicant's system does not require a fuel distributor instead, a separate fuel cap is used for each injector. The fuel cap delivers pressurized fuel to the injector as well as providing mechanical support for the injector.
4. requires a status sensing means for measuring a combination of air intake, engine temperature and vacuum in the intake manifold. The applicant's system does not monitor air intake, engine temperature of the manifold vacuum.
5. requires an ignition system. The applicant's system does not require that the engine have an ignition system.
For background purposes and as indicative of the art to which the invention is related, reference may be made to the remaining patents found in the search.
______________________________________ U.S. PAT. NO. INVENTOR ISSUED ______________________________________ 4,805,571 Humphrey February 1985 4,538,573 Merrick September 1985 4,546,746 Sato, et al October 1985 4,524,745 Tominari, et al June 1985 4,492,913 Arnold, et al January 1985 4,473,051 Chorman September 1984 4,446,833 Matsushita, et al May 1984 4,408,582 Merrick October 1983 4,347,823 Kessler, et al September 1982 4,341,193 Bowler July 1982 4,290,394 Frank, et al September 1981 4,284,053 Merrick August 1981 4,180,023 Kobayashi, et al December 1979 4,149,496 Palma April 1979 4,073,270 Endo February 1978 4,058,709 Long November 1977 ______________________________________